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Diane_

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So - can someone explain why a three s.d. number times a two s.d. number gives a two s.d. number?

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- Thread starter Diane_
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- #1

Diane_

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So - can someone explain why a three s.d. number times a two s.d. number gives a two s.d. number?

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HallsofIvy

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Enough with the platitudes!

Suppose your three s.d number is 1.43 x 10

Suppose we actually made the full error, high, in both cases. Then the actual value of the product is 1.435 x 10

That's a difference of 1.91 or about 2. Clearly saying that we know the value correct to the nearest 0.1 would be untrue. It's actually pushing it to say we have 2 s.f. since we aren't really certain that it must be between 67.5 and 68.5 which what "68" or "6.8 x 10

- #3

Diane_

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